Understanding is a fountain of life to one who has it, but the punishment of fools is their folly.
Understanding--or, "discretion," is a constant source of blessing (Pro 13:14), benefiting others; but fools' best efforts are folly.
Pro 16:22 22 A fountain of life is understanding to its possessor; But the correction of fools is folly. Oetinger, Bertheau, and others erroneously understand מוּסר of the education which fools bestow upon others; when fools is the subject spoken of, מוּסר is always the education which is bestowed on them, Pro 7:22; Pro 1:7; cf. Pro 5:23; Pro 15:5.
Understanding [is] a wellspring of life to him that hath it: but the instruction of fools [is] folly. (l) Either that which the wicked teach others, or else it is folly to teach them who are malicious.